How to Replace the Key Fob Battery in a Cadillac CT6

1. Press the button on the side of the RKE transmitter near the bottom and pull the key out.
2. Pry the two halves apart with a flat tool in the bottom center of the transmitter, not the key slot.
3. Remove the old battery without using a metal object.
4. Insert a new CR2032 or equivalent battery in the back housing with the positive side facing down.
5. Align the front and back housing and snap the transmitter together.
6. Reinsert the key.

• Replace the battery when the DIC displays REPLACE BATTERY IN REMOTE KEY.
• Do not touch the circuitry, since static could damage the transmitter.
• Never pull the key out without pressing the button.

Source: 2020 Cadillac CT6 owner's manual, PDF pages 17, 18. Steps are summarized in our own words (AI-assisted, checked against the cited pages 2026-10-18). Other model years can differ; your manual has the final word.